UV Photolysis of α-Cyclohexanedione in the Gas Phase

被引:12
作者
Mukhopadhyay, Anamika [1 ]
Mukherjee, Moitrayee [1 ]
Ghosh, Arup Kumar [1 ]
Chakraborty, Tapas [1 ]
机构
[1] Indian Assoc Cultivat Sci, Dept Phys Chem, Kolkata 700032, W Bengal, India
关键词
METHYL VINYL KETONE; QUANTUM YIELDS; ETHYL KETONE; I REACTIONS; PHOTOCHEMISTRY; ACETONE; NM; CYCLOPENTANONE; FEMTOCHEMISTRY; 4-HYDROXYANDROSTENEDIONE;
D O I
10.1021/jp201110p
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Ultraviolet absorption spectrum of alpha-cyclohexanedione (alpha-CHD) vapor in the wavelength range of 220-320 nm has been recorded in a 1 m long path gas cell at room temperature. With the aid of theoretical calculation, the band has been assigned to the S-2 <- S-0 transition of largely pi pi* type. The absorption cross section at the band maximum (similar to 258 nm) is nearly 3 orders of magnitude larger compared to that for the S-2 <- S-0 transition of a linear alpha-diketo prototype, 2,3-pentanedione. The photolysis was performed by exciting the sample vapor near this band maximum, using the 253.7 nm line of a mercury vapor lamp, and the products were analyzed by mass spectrometry as well as by infrared spectroscopy. The identified products are cyclopentanone, carbon monoxide, ketene, ethylene, and 4-pentenal. Geometry optimization at the CIS/6-311++G** level predicts that the carbonyl group is pyramidally distorted in the excited SI and S2 states, but the alpha-CHD ring does not show dissociative character. Potential energy curves with respect to a ring rupture coordinate (C-C bond between two carbonyl groups) for S-0, S-1, S-2, T-1, T-2, and T-3 states have been generated by partially optimizing the ground state geometry at DFT/B3LYP/6-311++G** level and calculating the vertical transition energies to the excited states by TDDFT method. Our analysis reveals that the reactions can take place at higher vibrational levels of So as well as T1 states.
引用
收藏
页码:7494 / 7502
页数:9
相关论文
共 47 条
  • [1] The photochemistry of acetone in the presence of water
    Aloisio, S
    Francisco, JS
    [J]. CHEMICAL PHYSICS LETTERS, 2000, 329 (3-4) : 179 - 184
  • [2] [Anonymous], 1995, Excited States and Photochemistry of Organic Molecules
  • [3] The photochemistry of formaldehyde: Internal conversion and molecular dissociation in a single step?
    Araujo, Marta
    Lasorne, Benjamin
    Bearpark, Michael J.
    Robb, Michael A.
    [J]. JOURNAL OF PHYSICAL CHEMISTRY A, 2008, 112 (33) : 7489 - 7491
  • [4] On interaction of 193 nm excimer laser with acetone (3s Rydberg state)
    Badr, Y
    Mahmoud, MA
    [J]. JOURNAL OF MOLECULAR STRUCTURE, 2005, 748 (1-3) : 189 - 193
  • [5] THE PHOTOLYSIS OF BIACETYL
    BELL, WE
    BLACET, FE
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1954, 76 (21) : 5332 - 5337
  • [6] THE PHOTOCHEMICAL DECOMPOSITION OF CYCLOHEXANONE, CYCLOPENTANONE AND CYCLOBUTANONE
    BLACET, FE
    MILLER, A
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1957, 79 (16) : 4327 - 4329
  • [7] BOUCHOUX G, 1987, NEW J CHEM, V11, P225
  • [8] Diau EWG, 2002, CHEMPHYSCHEM, V3, P57, DOI 10.1002/1439-7641(20020118)3:1<57::AID-CPHC57>3.0.CO
  • [9] 2-F
  • [10] Diau EWG, 2001, CHEMPHYSCHEM, V2, P294, DOI 10.1002/1439-7641(20010518)2:5<294::AID-CPHC294>3.0.CO